If the email will be read in a mobile device then I would keep it very short, so that it can be desplayed on one screen, without scrolling. How about this then:
Dear Supervisor,
I just wanted to update you on my training. This week, we have practiced on pacients, and specifically, we practiced explaining to patients the procedures, exchanging stitches and cleaning the wounds. I believe that this is very important experience for my career!
All the best,
your trainee